cities = {}
cities['Beijing'] = {'country': 'China', 'population': '21.89 million',
                     'fact': 'the regional gdp is 4026.96 billion yuan'}
cities['New York'] = {'country': 'America', 'population': '8.62 million',
                      'fact': 'the regional gdp is 801.7 billion dollar'}
cities['London'] = {'country': 'Britain', 'population': '8.9 million',
                    'fact': 'the regional gdp is 653.2 billion dollar'}
for city, info in cities.items():
    print(city + ':')
    for k, v in info.items():
        print('\t' + k + ': ' + v)
